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-rw-r--r--arch/mips/math-emu/dp_div.c143
1 files changed, 143 insertions, 0 deletions
diff --git a/arch/mips/math-emu/dp_div.c b/arch/mips/math-emu/dp_div.c
new file mode 100644
index 000000000..ac1ecc462
--- /dev/null
+++ b/arch/mips/math-emu/dp_div.c
@@ -0,0 +1,143 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* IEEE754 floating point arithmetic
+ * double precision: common utilities
+ */
+/*
+ * MIPS floating point support
+ * Copyright (C) 1994-2000 Algorithmics Ltd.
+ */
+
+#include "ieee754dp.h"
+
+union ieee754dp ieee754dp_div(union ieee754dp x, union ieee754dp y)
+{
+ u64 rm;
+ int re;
+ u64 bm;
+
+ COMPXDP;
+ COMPYDP;
+
+ EXPLODEXDP;
+ EXPLODEYDP;
+
+ ieee754_clearcx();
+
+ FLUSHXDP;
+ FLUSHYDP;
+
+ switch (CLPAIR(xc, yc)) {
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_SNAN):
+ return ieee754dp_nanxcpt(y);
+
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_SNAN):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_DNORM):
+ case CLPAIR(IEEE754_CLASS_SNAN, IEEE754_CLASS_INF):
+ return ieee754dp_nanxcpt(x);
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_QNAN):
+ return y;
+
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_QNAN):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_DNORM):
+ case CLPAIR(IEEE754_CLASS_QNAN, IEEE754_CLASS_INF):
+ return x;
+
+
+ /*
+ * Infinity handling
+ */
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_INF):
+ ieee754_setcx(IEEE754_INVALID_OPERATION);
+ return ieee754dp_indef();
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_INF):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_INF):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_INF):
+ return ieee754dp_zero(xs ^ ys);
+
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_INF, IEEE754_CLASS_DNORM):
+ return ieee754dp_inf(xs ^ ys);
+
+ /*
+ * Zero handling
+ */
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_ZERO):
+ ieee754_setcx(IEEE754_INVALID_OPERATION);
+ return ieee754dp_indef();
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
+ ieee754_setcx(IEEE754_ZERO_DIVIDE);
+ return ieee754dp_inf(xs ^ ys);
+
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_NORM):
+ case CLPAIR(IEEE754_CLASS_ZERO, IEEE754_CLASS_DNORM):
+ return ieee754dp_zero(xs == ys ? 0 : 1);
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_DNORM):
+ DPDNORMX;
+ fallthrough;
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_DNORM):
+ DPDNORMY;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_NORM):
+ DPDNORMX;
+ break;
+
+ case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_NORM):
+ break;
+ }
+ assert(xm & DP_HIDDEN_BIT);
+ assert(ym & DP_HIDDEN_BIT);
+
+ /* provide rounding space */
+ xm <<= 3;
+ ym <<= 3;
+
+ /* now the dirty work */
+
+ rm = 0;
+ re = xe - ye;
+
+ for (bm = DP_MBIT(DP_FBITS + 2); bm; bm >>= 1) {
+ if (xm >= ym) {
+ xm -= ym;
+ rm |= bm;
+ if (xm == 0)
+ break;
+ }
+ xm <<= 1;
+ }
+
+ rm <<= 1;
+ if (xm)
+ rm |= 1; /* have remainder, set sticky */
+
+ assert(rm);
+
+ /*
+ * Normalise rm to rounding precision ?
+ */
+ while ((rm >> (DP_FBITS + 3)) == 0) {
+ rm <<= 1;
+ re--;
+ }
+
+ return ieee754dp_format(xs == ys ? 0 : 1, re, rm);
+}